The key to any successful Web 2.0 deployment is the availability of an open
API . It's a key that Google is now giving out for its base -- Google Base that is.

The Google Base Data API is now freely available from Google, allowing third party developers to have applications that can interact with Google Base.

Developers can now programmatically query Google Base content as well as add, insert or delete content. As is the case with Google Maps, which has spawned a cottage industry of third party sites that "mashup" Google content for specific purposes, the availability of the Google Base Data API is likely to end up with its fair share of mashups as well.

Some have compared it to Craigslist while others have thought of it as potential competition for eBay.

Google Base, though, is neither.

According to Google's official description, "Google Base is a place where you can post all types of content and have it show up on Google."

Underlying the newly available Google Base Data API is Google's GData API, which, according to Google's definition, provides a simple standard protocol for reading and writing data on the web.

GData combines both Atom 1.0 and RSS 2.0 XML syndication formats in addition to a few extensions for dealing with queries.

"To acquire information from a service that supports GData, you send an HTTP
GET request; the service returns results as an Atom or RSS feed," Google's documentation states. "You can update data (where supported by a particular
GData service) by sending an HTTP PUT request, an approach based on the Atom
Publishing Protocol."

GData is already used in the Google Calendar API and Blogger Data API among other Google services.